Changes in Power Plant NO_x Emissions over Northwest Greece Using a Data Assimilation Technique

Round 1

Reviewer 1 Report

This paper is well written in terms of structural and technical level. Also, it is a very interesting and meaningful attempt for the authors to monitor NOx emissions using the data assimilation technique based on the ensemble Kalman filter method.

 

However, the authors need to improve the following points. If the authors accept them, I believe that this paper will be a good paper that meets the requirements of Atmosphere.

 

First, the authors need to rewrite the introduction and conclusions more clearly for the readers of this journal.

 

Second, the authors need to describe in more detail the theoretical and practical contributions of this study.

 

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

This manuscript is well-written and well-organized to detect the changes of power plant NOx emissions over Northwest Greece using TROPOMI satellite measurement and LOTUS-EUROS model simulation with EnKF. I would like to recommend the publication, but please consider following one major comment and several minor points. Major comments: Configuration of emission from power plant: Because this study focuses on the power plant emissions, it is required to explicitly show the vertical allocation of emissions from power plant sources. On L171, the temporal variation is stated, but how about the vertical layers for power plant? Is it taken into account each stack height? Please describe. Minor comments: Fig. 1: It is kind to add city lines to distinguish the investigated areas. L121-129: I guess that the lifetime is also an important point for targeting summer rather than winter. Do you have additional comments to this paragraph? L148-154: The model simulation in [14] is different from configuration in this study? If using similar configurations, these lines are appropriate to put after L178 to reinforce the validity of this modeling system. L181-183: This information is also needed in the caption (L185-186). L256: The abbreviation of “(AK)” can be moved here from L296. L502-537: Are the usage of bold fonts possible in this journal? Please confirm the journal guideline. Technical comments: Throughout the manuscript, the unit of column amount should be unified, I saw several expressions of “molec.cm-2”, “molec/cm2”, “molecules/cm2”.

Author Response

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Author Response File: Author Response.pdf

Reviewer 3 Report

Manuscript ID: atmosphere-1265857. Changes in power plant NOx emissions over Northwest Greece using a data assimilation technique.   

In this study, they estimate NOx emission changes in Northwest Greece based on the high spatial resolution Sentinel-5 Precursor (S5P) Tropospheric Monitoring Instrument (TROPOMI) observations and simulations using the LOTOS-EUROS Chemical Transport model. In this work, the emissions are studied for the summer periods (i.e. June, July and 121 August) of 2018 and 2019 and the data assimilation technique applied is a Local Ensemble 122 Transform Kalman Filter system developed around the LOTOS-EUROS CTM.

Comments:

1. L23-25. Check wording. confused.
2.  Please avoid repeating terms, keywords and title. L36-37.
3. I suggest increasing the size of the text in Figure 1. It is not visible.
4. A detailed description of the study site is provided in the introduction. This information should be transferred to the Materials and Methods chapter. There should be a description of the study site.
5. In the introduction please increase the references in relation to the subject of study. Similar experiences?
6. Currently the introduction is extensive.
7. It seems that the objective of this work is dispersed throughout the introduction. Please state this clearly at the end of the introduction.
8. L157. Add space between words: x5 km...
9. The captions of the figures are extensive. Please synthesize.
10. The results chapter should be called: Results and discussion.
11. The results chapter has too many figures. Some could be moved to supplementary material?
12. The conclusions of the work are very extensive. Please synthesize. This will give greater clarity.
13. It is suggested to revise the wording of the entire manuscript. This must be clear and concrete. Currently the manuscript is difficult to follow.

Author Response

"Please see the attachment

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

I appreciate the revision to fully address my concerns.

The revised manuscript showed "Error! Reference source not found." in some points, so please carefully confirm these points in the final production process.